Eh, I think it's been okay this year. So far, there haven't been any major controversies that have shown up on ESPN or CNNSI that I've seen. Replay has been pretty good for the league with the following caveats:
1) It *does* slow down the pace of the game and can impact teams on hot drives
2) Some plays can't be reviewed -- those based on subjective judgement, like PI
3) When the whistle blows, nothing else counts, no replay no nothing
Officiating in the NFL hit a new low one or two years ago. There were just so many questionable calls -- do you remember when Phil Luckett screwed up the coin toss?